2010 Toyota Matrix Owners Manual - Page 119

1-7. Safety information Child restraint systems with a top tether strap STEP 1 Secure the child restraint using the seat belt lower anchors, and remove the head restraint. STEP 2 Open the anchor bracket cover, latch the hook onto the anchor bracket and tighten the top tether strap. Make sure the top tether strap is securely latched. STEP 3 Replace the head restraint.